Hi everyone!
I'm trying to block mesh a configuration which is a hemisphere connected to a radiused cylinder, which in turn is connected to a box. I start of with doing two splits, separating the box from the cylinder and separating the cylinder from the hemisphere, the hemisphere block contains also the radiused part of the cylinder.

My strategy then has been to do an O-grid split of everything, remove the excess elements around the cylinder and hemisphere, and the associate the faces and edges. For the block with the radiused part, I set the "long" edge on the block to project onto the faces of the radiused cylinder and the circular flat surface of the hemisphere, then I let the "end" face of the block to project upon the hemisphere, I associate the edges accordingly.

So my mesh then becomes very ugly due the fact that I'm projecting a square face of the block upon a curved round surface. I've understood that I should have an O-grid split on the face of the hemisphere(and I actually need an o-grid in the cylinder as well to put in BL) but then when I do it, the elements become twisted and weird and I get a negative 2x2x2 determinants and get volume orientation errors when checking the mesh.

I tried a blocking with bottom up method. I started with a 2D blocking (att1) for the hemisphere and rotated it to 3D (90 degrees). After that I copied it by rotation three more times to get the full 360 degrees. The very inner blocks have to be deleted as they are degenerated (triangle blocks).

The further process is adding Ogrid, doing associations, extruding the blocking into the squared region and merging the vertices of the extruded blocks (merge by tolerance). I also had to link some edges.

Thanks kad once again! You've helped me numerous times with the blocking, I owe you one!
Your approach looks nice, I never thought on doing bottom up and have always tried top down. Thanks for adding to my knowledge!